The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
The present invention relates to the field of calculating aerodynamic performance of an aircraft. More particularly, the invention relates to a system and method for calculating aerodynamic performance of a tilting wing aircraft.
Design of an aerodynamic vehicle such as a short takeoff and landing (STOL) aircraft is extremely complex and involves the evaluation of hundreds of configurations. For each configuration option, hundreds or even thousands of conceptual designs must be evaluated. One configuration option for a STOL aircraft design is a tilting wing configuration, which maximizes the use of the wing surface for lift generation. The tilting wing configuration adds further complexities to the design process as compared to the conventional fixed wing aircraft. For example, various aerodynamic performance parameters must be evaluated over the translation range of the tilting wing. The evaluation includes calculating lift, drag, pitching moment or the like.
One proposed method to conduct such evaluation would be to fabricate a model of each conceptual design and conduct wind tunnel testing. However, the fabrication and wind tunnel testing of each conceptual design model would be extremely time-consuming and expensive. Alternatively, a computer model of each conceptual design may be made and tested using empirical methodologies developed from blown-wing STOL configuration investigations. Currently, multiple methodologies must be used. Further, most methodologies focus on calculating lift, drag and the piece wise contributions of different phenomena (i.e., vectored thrust, induced vorticity, angle-of-attack, etc.) to the total axial and normal force.
Other parameters such as trim and moment calculations, which are critical to STOL configuration development and evaluation, require accurate estimation of the effective points of action. In the case of blown wings, most of these force locations fluctuate as functions of blowing coefficient, local geometry, and angle-of-attack. At lower speeds and high-power settings inherent in STOL operations, small force contributions normally negligible in conventional flight may become key elements in general stability characteristics and functional control effectors. Most methodologies do not adequately calculate the effective points of action for trim and moment calculations for blown wing configurations, in particular, the low airspeed and high-power setting conditions.
Therefore, there exists a need in the art for a system and a method that makes inter-related calculations of thrust, normal force, axial force, pitching moments, trim and flight path angle as functions of airspeed and tilt angle.
The principal object of the present invention is to provide a system and a method that calculates aerodynamic performance parameters for aircraft configurations.
According to one aspect of the invention, the invention is an aerodynamic performance system in a workstation which includes a processor circuit having a processor and a memory. Additionally, the system includes aerodynamic performance logic stored on the memory and executable by the processor. The aerodynamic performance logic includes logic that calculates a number of aerodynamic performance parameters for a configuration. Further, the logic generates an aerodynamic performance report to be sent to a client via a network. The aerodynamic performance report lists at least one of the aerodynamic performance parameters.
According to another aspect of the invention, the aerodynamic performance system calculates the aerodynamic performance parameters for a configuration on a computer system.
According to yet another aspect, the logic calculates a number of aerodynamic performance parameters in a number of configurations wherein the logic compares the aerodynamic performance parameters of at least one of the configurations with the aerodynamic performance parameters of another configuration.